Crustal Imaging Through Geotomography and Wavefield Migration of Reflected Head Waves: Application to the Kentland Dome

在之前的国家科学基金会资助下，我们进行了一项新的实验，研究印第安纳州肯特兰附近一个化石陨石坑的中央隆起区域的内部结构。我们要求基金使用三种工具来分析这些数据，以完善我们对其结构的了解。(1)利用常规方法分析了8英里的反向折射和分裂折射数据，以解决1.5英里乘2英里矩形研究区域边缘周围的结构细节。(2)应用了一种名为扇射地质层析成像的新技术，该技术可用于反演折射层深处穿过地球的二维切片上的横向速度变化。(3)横向反射头波成像新波场偏移技术的开发与应用。利用这种技术，我们希望能以与地下分层法向反射数据图像相当的分辨率，沿着地球的水平切片对主要的横向不连续面进行成像。后两种技术需要一些额外的技术开发。随着技术的进一步发展，这些技术在今后岩石圈结构的大规模研究中可能具有应用价值。

Under previous NSF funding we conducted a novel experiment to study the internal structure of what appears to be the central uplift region of a fossil meteor crater near Kentland, Indiana. We request funds to analyze these data to refine our knowledge of their structure using three tools. (1) Analysis of 8 miles of reversed and split refraction data using conventional methods to resolve structural details around the edges of 1.5 by 2 mile rectangular study area. (2) Application of a new technique called fan shot geotomography that can be used to invert for lateral velocity variations on a two dimensional slice through the earth at the depth of the refracting layer. (3) Development and application of a new wavefield migration technique for imaging laterally reflected head waves. With this technique we hope to image major lateral discontinuties along a horizontal slice through the earth with a resolution comparable to normal incidence reflection data images of subsurface layering. The later two techniques require some additional technical development. With further development these techniques may prove valuable for application to future large scale investigations of lithospheric structure.